微电网的综合控制策略研究

发布时间：2018-03-09 12:26

本文选题：微电网　切入点：改进的电压电流双环控制　出处：《南京理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：微电网不仅能够展现和发挥分布式发电的优点,而且可以减小分布式发电对电网的冲击和不利影响,它将地理分散、一次能源多种多样的分布式电源整合在一个区域网络里,并对网络内的电压与能量进行统一地管理和调度,成为一种新颖的电力系统组织方式和结构。论文首先分析了三相全桥逆变器的电路拓扑结构,然后在此基础上建立离散的平均状态空间模型。在传统电压电流双环控制方法的基础上加入无差拍控制并将负载电流作为附加指令,提出了一种改进的电压电流双环控制策略。通过仿真验证,改进的电压电流双环控制能够及时追踪参考指令,动态响应能力快速,并具有良好的稳定性。然后研究了Vf控制器和PQ控制器的设计方法,搭建仿真模型并对参考电压变化、参考功率变化以及改变负荷三种情况进行仿真,验证了两种控制器的有效性。除此之外,还对微电网主从控制策略进行建模仿真,得出所设计的Vf控制器能够及时追踪参考电压,保证了离网运行时微电网电压幅值和频率稳定；在并网运行时,分布式电源切换为PQ控制,能够维持各自输出功率按设定值稳定运行。接着分析了微电网下垂控制和倒下垂控制原理,并分别建立仿真模型,对投切负荷情况进行仿真,验证了这两种控制方法的有效性。然后采用对等控制对微电网并／离网两种运行工况以及两种工况切换进行仿真分析,仿真结果表明所设计的控制策略能够使微电网稳定运行。最后针对传统下垂控制方法的不足,设计了一种基于单神经元自适应PID控制的改进下垂控制器。在此基础上建立模型并对投切负荷情况进行仿真,与采用传统的下垂控制相比,得出了无论稳态运行还是系统发生扰动,该下垂控制器均能体现出良好的鲁棒性、跟踪性能和动态响应能力。
[Abstract]:Microgrid not only can show and play the advantages of distributed generation, but also can reduce the impact and adverse effects of distributed generation on the grid. And the voltage and energy in the network are managed and dispatching uniformly, which becomes a novel power system organization and structure. Firstly, the circuit topology of three-phase full-bridge inverter is analyzed. Then the discrete average state space model is established. The deadbeat control is added on the basis of the traditional voltage and current double loop control method and the load current is taken as the additional instruction. An improved double loop control strategy for voltage and current is proposed. The simulation results show that the improved double loop control can track the reference instructions in time, and the dynamic response is fast and has good stability. Then, the design method of VF controller and PQ controller is studied, and the simulation model is built, and the reference voltage change, reference power change and load change are simulated to verify the effectiveness of the two controllers. By modeling and simulating the master and slave control strategy of microgrid, it is concluded that the designed VF controller can track the reference voltage in time and ensure the stability of voltage amplitude and frequency in off-grid operation. The distributed power supply is switched to PQ control, which can keep the output power running stably according to the set value. Then, the principle of droop control and inverted droop control of microgrid are analyzed, and the simulation models are established to simulate the load shedding. The effectiveness of these two control methods is verified, and then the simulation analysis of two operating conditions and switching of two operating conditions is carried out by using peer-to-peer control. The simulation results show that the proposed control strategy can make the microgrid run stably. Finally, an improved sagging controller based on single neuron adaptive PID control is designed to overcome the shortcomings of traditional droop control methods. Compared with the traditional droop control, it is concluded that the sagging controller can show good robustness, tracking performance and dynamic response ability, regardless of the steady state operation or the disturbance of the system.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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